Apparatus for oxygen conversion of iron to steel



J. WALKER Dec. 14, 1965 APPARATUS FOR OXYGEN CONVERSION OF IRON TO STEEL Filed Nov. 26. 1962 PIE. 1

INVENTOR.

JOHN WALKER United States Patent 3,223,399 APPARATUS FOR OXYGEN CONVERSIGN OF IRON T0 STEEL John Walker, Walnut Creek, Caiifl, assignor, by mesne assignments, to Kaiser Industries Corporation, Oakland, Calif., a corporation of Nevada Filed Nov. 26, 1962, Ser. No. 261,242 5 Claims. (Cl. 26636) This invention relates to apparatus for conversion of iron to steel, and particularly to a vent assembly used in conjunction with a conversion vessel.

In one process for converting iron to steel purified oxygen is blown against the surface of a charge contained in a refractory lined conversion vessel that is pivoted to be moved between a vertical operating or converting position and a tilted pouring or discharging position. The conversion vessel is charged through an open mouth with the proper ingredients to form steel after :hich a stream of oxygen is directed against the surface of the charge-to eiiect the conversion of the charge to steel. Oxygen is introduced into the vessel through a conduit called a lance, which is usually cooled to prevent its destruction and placed within the vessel a suitable distance above the charge.

The process is accompanied by the evolution of hot gases and means must be provided for collecting and removing these gases. Accordingly, a vent or duct system is usually positioned with respect to the mouth of the vessel to collect the gases and transport them from the vessel when the vessel is in the operating position and the lance is inside of it.

The oxygen lance ordinarily extends through a part of the overall gas vent or the hood part of the vent in passing into the mouth of the vessel and it is, therefore, necessary to move the tip of the lance to the height of the lance opening in the hood in order to have it enter the vessel. The higher that the lance opening in the hood is above the vessel mouth, the longer the lance must be to extend from the lance opening in the hood down to its operating position above the charge in the vessel. The length of the lance and the height to which it must be raised in order to get it into the vessel are important factors in determining the height of the building in which the process using such a lance is to be performed as well as the size of the lance-handling equipment that must be employed. Any reduction in the length of the lance or in the distance that it must be raised, therefore, produces significant savings in the cost of the processing equipment and the structure surrounding and housing it.

The apparatus of this invention reduces substantially or eliminates completely the additional height above the mouth of the conversion vessel to which a lance must be raised in order for it to be inserted into the hood portion of the gas-collecting means or vent and the conversion vessel associated therewith. The apparatus of this invention includes a shallow hood placed closely adjacent or about the mouth of the conversion vessel when the vessel is in converting position so that the hood is positioned to collect the gases evolved from the process. The shallow hood has a plurality of openings through it, two of which are large openings which provide a passageway from the hood to the vent assembly that is used to carry the gases evolved from the process. Preferably, these openings are connected to ducts which are part of the same vent system and which are ultimately joined in a common conduit at some position remote from the hood.

The third opening is a relatively small and medially placed aperture which is a lance-receiving aperture through which the lance passes into the vessel. The aperture is preferably adapted to receive both the lance 3,223,399 Patented Dec. 14, 1965 and a releasable clamping means for the lance so that it not only prov-ides a means for a lance to enter the vessel, but also a means to maintain the lance in its proper position. By providing a shallow hood spaced closely above the conversion vessel and a plurality of ducts carrying the gas evolved in the process from beneath the hood, a centrally spaced aperture for the lance to enter the vessel through the hood can advantageously be positioned only slightly above the mouth of the vessel, and the lance need not be raised significantly higher than the mouth of the vessel in order for it to be passed through the opening provided for it in the hood.

In another embodiment of this invent-ion, advantage is taken of the plural duct structure to provide a segmented hood which may be separated into at least two hood segments that are movable from their position over the conversion vessel. The hood segments are extendable to and retractable from an extended position in which they join to form a complete hood over the conversion vessel. In a preferred embodiment means are associated with two segments which act cooperatively in the joined position to form a lance-receiving opening or aperture. A hood with retractable hood segments still further reduces the height to which the lance must be raised for insertion and removal in a conversion vessel. With the segments separated the lance need only be raised high enough to clear the mouth of the conversion vessel.

This invention also provides, in one embodiment, a

recess in the hood which acts cooperatively with a releasable conical clamping means for the oxygen lance whereby the oxygen lance will be held firmly in any vertical position and centered in the recess or aperture in the hood that is adapted to receive it.

The accompanying drawings are presented to show an apparatus embodying this invention and are presented as illustrative of the invention rather than limiting in any way upon its scope.

FIG. 1 is an elevation view of an apparatus embodying this invention showing in phantom a second position that may be occupied by a portion of the device,

FIG. 2 is a view in elevation of a suitable releasable 1gliamplused in conjunction with the apparatus shown in And FIG. 3 is a partial perspective view of two clamp lsegments in locking engagement with a portion of a ance.

In FIG. 1 a conversion vessel generally designated 10 is shown vertically oriented with a mouth 11 opening upwardly. The vessel is supported between trunnions 12 for pivotal movement around the axis of the trunnions so that it may be moved from the vertical position in which processing is effected to a tilted pouring position for discharging the product of the process.

The conversion vessel or converter 10 has a hood 13 disposed closely above it for collecting the gases evolved during the process. This hood 13 has a shallow vertical dimension so that the upper surface 15 of the main hood chamber 15' is not greatly elevated above the open mouth 11 of the conversion vessel. The upper surface 15 has a plurality of openings in it. Two of these openings 14 and 14' are connected in gas conducting relationship with duct members 16 and 17 which collect the gases entering the hood chamber 15' from the converter. Ducts 16 and 17 diverge from hood 13 and ultimately may discharge into a common gas venting system. A third opening 18 is positioned in the central portion of the hood 13. The opening 18 is small compared with the openings for the ducts 16 and 17 being only large enough to easily accommodate a lance 20. In a preferred embodiment a split tapered clamping ring 21 is employed which fits within an opening or aperture 18 provided in hood 13 between ducts 16 and 17 to hold the oxygen lance 20. The ring 21 can be formed of two identical halves, each as shown in FIG. 2. The halves, when positioned around a lance with surfaces 22 abutting or facing each other form a truncated cone with an axial cylindrical bore 23. The bore 23 may be provided with suitable lance gripping means such. as the ridges shown in FIG. 2.

FIG. 1 shows in phantom another embodiment of this invention, the hood 13 may be constituted of two hood segments 25 and 26, each of which includes a duct. These hood segments desirably include lower symmetrical halves or half sections 19 and 19 depending from a duct 16 or 17 as the case may be, and they are movable into and out of contact to form the main hood chamber 15. Suitable recesses 24 and 24' are provided in the tops of the half sections 19 and 19 to form the lance-receiving opening 18. For this purpose, segment 25 provided with duct 16 is provided with a connecting element 27 which connects duct member 16 to a rod 28 which in turn is extended or retracted by a force exerting means such as a pneumatic or hydraulic cylinder, which is not shown. A connecting element 30 employed in conjunction with a rod 31 connects to another force exerting means which is not shown, to efiect movement of the hood segment 26 provided with duct 17. The duct 16 must be rotatably connected at 32 and the duct element 17 must be rotatably connected at 33 in order for the duct elements 16 and 17 and their associated hood elements 25 and 26 to be rotated to the inoperative positions shown in phantom in FIG. 1. When the vent elements 16 and 17 are rotatable the lance 20 may be completely freed from the hood 13 and removed from the interior of vessel by being raised only high enough to clear the mouth 11. In addition to this advantage, moving the hood segments 25 and 26 into the positions shown in phantom provides clear access to the mouth 11 so that the interior of the vessel 10 is available for loading, unloading, inspection or maintenance without being obstructed by the usual vents and hoods previously used.

In the operation of the illustrated device the vessel 10 is charged or loaded with pig iron and other materials required for the production of steel. When the vessel is loaded, the lance 20 is raised to a position immediately above opening 18 and lowered through the opening 18 in the hood 13 and into the vessel 10. The two segments 21 which form a split conical ring are then placed around the lance 20 and within the opening 18. The segments 21 are maintained loosely around the lance until the precise position that it will occupy during processing is established after which the segments 21 are forced into contact with the lance 20 and the lance and segments are moved into the opening 18. The coaction of the opening 18, the tapered split ring segments 21 and the lance cause the interior rough surface 23 of the split conical ring to grasp the exterior surface of the lance firmly and prevent it from moving downwardly into the vessel. The tapered split ring segments also center the lance in the opening 18 whereby it is oriented both with respect to its position from side to side of the vessel and its position above the surface of the charge. Instead of surfaces 23 the ring sections 21 can be threaded so as to mate with correspondingly threaded portions on the lance 20.

Oxygen is then passed through the lance and blown against the surface of the charge to eifect conversion of the charge to steel. The gas evolved during the process passes from mouth 11 after which it is collected in the hood 13 and passed to the venting assembly through duct elements 16 and 17. When the process is complete, lance 20 is raised only high enough to clear the upper surface of the hood chamber 15' in the hood 13 and removed from the interior of the vessel 10 after which the molten contents of the vessel may be discharged by rotating the vessel on the trunnions 12.

In the embodiment of this invention wherein the hood 13 is constituted of separable hood segments 25 and 26 the process is similarly effected, however, the lance need be raised only high enough to clear the upper portion of the vessel 10. During the portion of the process when the vessel 10 is being charged, the ducts 16 and 17 normally will occupy the positions shown in phantom. After the conversion vessel 10 is charged, the lance is placed within the vessel, being raised only far enough to clear the open mouth 11, and when it is positioned approximately as desired, the force exerting means extend the rods 28 and 31 to force duct members 16 and 17 respectively toward each other until the segments 25 and 26 join to form a hood. Each of the hood segments 25 and 26 preferably carries a shaped aperture segment 24 and 24" and when the hood segments are joined, the aperture segments form an aperture 18 surrounding the lance. The split ring elements 21 may then be placed in contact with the lance and the final positioning of the lance may be made as described above.

When the conversion process is complete, the hood segments may be separated by operation of the force exerting means and the lance removed by raising it only as high as the mouth of the vessel after which the vessel may be discharged as hereinbefore described.

Tapered split ring segments 21 advantageously are provided with engaging means 37 for moving the elements out of the aperture 18. The engaging means may be connected to rods, cables or similar means for manipulating ring elements 21 when it is desired to change the position of the lance 20. Motion of the lance 20 toward vessel 10 will tend to lock the clamp formed of segments 21 more firmly. Therefore, when it is desired to adjust the position of the lance 20 by inserting it farther into the vessel 10, the clamp segments 21 must be slightly raised to release the lance. The lance 20 may however be withdrawn either entirely or partly from the vessel 10 without deliberately releasing the clamp formed by segments 21 because the withdrawing motion of the lance automatically causes such release.

What is claimed is:

1. In an apparatus for oxygen conversion of iron to steel the combination of a conversion vessel pivotally mounted to be movable from a normal steel converting position to a tilted pouring position, said vessel also being provided with a mouth at the upper portion thereof, a shallow hood disposed in gas-collecting position with respect to said mouth when said vessel is in said normal steel converting position, said hood com-prising separable segments that are extendable to and retractable from .a joined position in which they form said hood, each segment including a duct, said segments when in joined position providing a gas-collecting chamber superposed about the month of said vessel, the hood formed by said segments further including an aperture for receiving a lance.

2. The apparatus of claim 1 further characterized in that each hood segment includes a shaped aperture element which is so positioned that said aperture elements cooperate to form said aperture when said hood segments are extended and joined.

3. The apparatus of claim 1 further characterized in that said aperture in said hood is larger than the major cross-sectional dimension of said lance, a clamp releasably fixed to said lance and said clamp being of such a size that it cannot completely pass through said aperture when said clamp is fixed to said lance.

4. The apparatus of claim 3 further characterized in that said clamp is comprised of tapered segments which closely embrace said lance, said segments when in a lanceembracing position also being receivable in the lancereceiving aperture of said hood.

5. The apparatus of claim 1 further characterized in that said aperture is disposed in coaxial alignment with the mouth of said vessel when said vessel is in a normal steel converting position.

References Cited by the Examiner UNITED STATES PATENTS McKelvey 26631 McFeaters 266--34 Konig 98-115 X 6 3,002,739 10/1961 Lawler 26635 3,138,649 6/1964 Erni 98115X FOREIGN PATENTS 566,916

5/1958 Belgium.

JOHN F. CAMPBELL, Primany Examiner. JAMES H. TAYMAN, JR., MORRIS O. WOLK,

Examiners. 

1. IN AN APPARATUS FOR OXYGEN CONVERSIN OF IRON TO STEEL THE COMBINATION OF A COVERSION VESSEL PIVOTALLY MOUNTED TO BE MOVABLE FROM A NORMAL STEEL CONVERTING POSITION TO A TILTED POURING POSITION, SAID VESSEL ALSO BEING PROVIDED WITH A MOUTH AT THE UPPER PORTION THERE-P OF, A SHALLOW HOOD DISPOSED IN GAS-COLLECTING POSITION WITH RESPECT TO SAID MOUTH WHEN SAID VESEL IS IN SAID NORMAL STEEL CONVERTING POSITION, SAID HOOD COMPRISING SEPARABLE SEGMENTS THAT ARE EXTENDABLE TO AND RETRACTABLE FROM A JOINED POSITION IN WHICH THEY FORM SAID HOOD, EACH SEGMENT INCLUDING A DUCT, SAID SEGMENTS WHEN IN JOINED POSITION PROVIDING A GAS-COLLECTING CHAMBER SUPERPOSED ABOUT THE MOUTH OF SAID VESSEL, THE HOOD FORMED BY SAID SEGMENTS FURTHER INCLUDING AN APERTURE FOR RECEIVING A LANCE. 